THE THESAUROFACET: A MULTIPURPOSE RETRIEVAL LANGUAGE TOOL

A description is given of the English Electric ‘Thesaurofacet’, a faceted classification and thesaurus covering engineering and related scientific, technical, and management subjects. A novel feature of the system is the integration of the classification schedules and thesaurus. Each term appears both in the thesaurus and in the schedules. In the schedules the term is displayed in the most appropriate facet and hierarchy: the thesaurus supplements this information by indicating alternative hierarchies and other relationships which cut across the classified arrangement. The thesaurus also controls word forms and synonyms and acts as the alphabetical index to the class numbers. The resulting tool is multipurpose, as easily applicable to shelf arrangement and conventional classified card catalogues as to co‐ordinate indexing and computerized retrieval systems. The reasons are given for modifying certain traditional facet techniques, including the choice of traditional disciplines for main classes, the lack of a ‘built‐in’ preferred order, and the me, in certain instances, of enumeration rather than synthesis to express multi‐term concepts. Methods of application of the Thesaurofacet in pre‐coordinate and post‐coordinate systems are discussed and a brief account is given of the techniques employed in its compilation.